In the prior process, an etching liquid or gas will spray and flush a substrate which is conveyed through a wet etching device. In order to reduce vibration of the substrate during conveyance, a double-roller structure is usually desired to provide support for the substrate, so as to improve stability of the substrate during conveyance.
The double-roller structure of the prior art is designed as shown in FIG. 1, wherein a position of a lower roller 102 is fixed, while an upper roller 101 is movable up and down relative to the lower roller 102, and an upper roller shaft 103 and a lower roller shaft 104 are provided with shaft support brackets 105 at respective ends thereof. In the prior art, a clearance between two rollers is increased or reduced by increasing or reducing gaskets 106 between the shaft support brackets 105, or by raising or lowering a position of the upper roller 101 via adjusting an adjusting bolt 107 provided on the shaft support brackets 105 corresponding to the upper roller 101.
Currently, substrates tend to be diversified in size and thickness and the clearance between two rollers requires frequent adjustments during production according to the thickness of different substrates. The discussed prior adjustment methods mainly have the following defects: firstly, rollers disposed within the wet etching device makes it difficult to increase and decrease gaskets or to provide an adjusting bolt, and frequent manual operations within the device may easily pollute the inner circumstance, influence quality of products and waste human and material resources; secondly, in the prior art, the adjustment result is manually confirmed with a feeler gauge, which is low in precision and greatly different in personnel operations, thus the substrate can be easily damaged when the clearance between two rollers is abnormal, thereby causing product loss and reducing operation ratio of the device; further, the prior art cannot measure a pressure of the roller on the substrate, which may go against clearance adjustment and analysis after chippings occur.